1. Field of the Invention
The present invention relates to a paper feed and output assembly which supplies and delivers recording paper, and also relates to an image forming apparatus.
1. Related Art
This type of image forming apparatus often combines a copier function, a printer function, a facsimile transmission function and more, due to the development of multifunction devices. Alternatively or additionally, the image forming apparatus may have other functions of feeding recording paper of various sizes selectively from separate paper cassettes and sorting printed paper into more than one bin sorter. On the other hand, the market has strongly requested compact image forming apparatus. However, these paper cassettes and bin sorters are too bulky to realize miniaturization of the image forming apparatus.
FIG. 8 is a side view which exemplifies such a conventional image forming apparatus. This image forming apparatus is equipped with a document feeder 101 in which an original document is placed, a scanner 102 for scanning an original document, paper cassettes 103 for separately storing recording paper of various sizes, a transport unit 104 for pulling out and transporting recording paper from any of the paper cassettes 103, a printer 105 by which an image of an original document scanned by the scanner 102 is recorded on recording paper which is transported from the transport unit 104, and an output unit 106 for handling printed paper. The output unit 106 delivers printed paper from an output port 107 to a top output tray 108 or from an output port 110 to any of bin sorters 109. In the latter case, a suitable bin sorter 109 is vertically displaced to the output port 110 so as to receive printed paper therefrom.
As apparent from FIG. 8, the paper cassettes 103 and the bin sorters 109 occupy an enormous space relative to the entire image forming apparatus, hindering miniaturization of the image forming apparatus.
In this respect, techniques for producing a compact image forming apparatus are proposed in Japanese Patent Laid-open Publication Nos. H2-286546 and H2-178149, to name a few. These techniques utilize a single tray as a paper cassette and as an output bin. The single tray supplies pre-printed paper to the image forming apparatus and receives printed paper therefrom.
However, since the single tray combines the functions of a paper cassette and an output bin, the techniques disclosed in these publications fail to impart sophisticated functions of feeding recording paper of various sizes selectively and sorting printed paper.